vtn/opencl: Hook up OpenCL async copy and group wait opcodes via libclc

Adds an additional hook for spirv_to_nir to handle a core opcode via
the OpenCL libclc infrastructure, and adds handling for SpvOpGroupAsyncCopy and
SpvOpGroupWaitEvents.

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6035>
3 files changed